(RFE/RL) -- The H1N1 strain of influenza, popularly known as swine flu, is continuing to spread around the globe in an unspectacular but persistent way.
Experts estimate that more than 1 million people have been infected, although fewer than 500 are confirmed to have died.
The World Health Organization (WHO) has labeled the new strain "unstoppable" and declared on July 11 a global pandemic. One of the most troubling aspects of the situation is that no specific vaccine against it has yet been developed, and even when it is, distributing it around the world will be a massive and slow undertaking.
The ratio of confirmed deaths to the estimated number of infections is presently so small that -- even if the swine flu continues to spread -- one could be lulled into a belief that things are not too disturbing.
After all, "normal" seasonal flu accounts already for tens of thousands of deaths per year worldwide, and the new H1N1 strain would seem to be adding only slightly to that statistic.
But that idea would be wrong, according to medical historian John Barry of the Tulane/Xavier Center for Bioenvironmental Research in New Orleans.
"People say, 'Oh, well that's nothing to worry about then.' That's not exactly true, because people are protected against seasonal influenza. Whether they are vaccinated or not, their immune system has seen that virus before and it gives them significant protection," Barry says.
"This new virus is something nobody has ever seen before. So even if it is mild, it is going to infect so many more people if it becomes fully adapted that there will still be a significant death toll."
A report issued by a team of U.S. and Hong Kong medical researchers goes further. They have studied the major flu epidemics of the last century, particularly the cataclysmic event of 1918-19, in which some 50 million people are estimated to have died.
They say that the deadly flu strains involved had been circulating for some years beforehand in less dangerous forms. But they underwent several "re-assortments" before taking on their most virulent form. That means that different flu viruses were able to swap genetic material when a host -- either a person or an animal -- was infected by two strains at the same time.
The import of that is that we are facing the possibility of a much more dangerous pandemic than presently seems the case. And we are not yet equipped for that.
'Poor' Vaccine Production
The head of the WHO's Initiative for Vaccine Research, Marie-Paule Kieny, said in London on July 12 that a fully licensed swine-flu vaccine might not be available until the end of the year. She said production of the ingredient required in the vaccine has been "poor."
Yields from growing the new virus needed for the vaccine had been less than 50 percent of that obtained with normal seasonal flu strains. She said the big drugs research companies are now studying alternative strains that will hopefully increase output.
The WTO has previously said every country in the world will need doses of the vaccine.
Kieny said doctors, nurses, and other healthcare workers should get priority doses, so that they are fit to cope with an outbreak in the general population.
Preparations for the peak flu season in autumn are going forward in many countries. Business groups in Belgium expect one in four workers to be hit by illness.
In Italy, the government has already said it will give priority to "essential" personnel, such as police officers, firefighters, and health workers. Also in that category would be people with a prior illness.
RFE/RL correspondent Ron Synovitz contributed to this report